1 //===-- X86TargetFrameLowering.h - Define frame lowering for X86 -*- C++ -*-==//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This class implements X86-specific bits of TargetFrameLowering class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_X86_X86FRAMELOWERING_H
15 #define LLVM_LIB_TARGET_X86_X86FRAMELOWERING_H
16 
17 #include "llvm/Target/TargetFrameLowering.h"
18 
19 namespace llvm {
20 
21 class MCSymbol;
22 class X86TargetMachine;
23 class X86Subtarget;
24 
25 class X86FrameLowering : public TargetFrameLowering {
26 public:
X86FrameLowering(StackDirection D,unsigned StackAl,int LAO)27   explicit X86FrameLowering(StackDirection D, unsigned StackAl, int LAO)
28     : TargetFrameLowering(StackGrowsDown, StackAl, LAO) {}
29 
30   /// Emit a call to the target's stack probe function. This is required for all
31   /// large stack allocations on Windows. The caller is required to materialize
32   /// the number of bytes to probe in RAX/EAX.
33   static void emitStackProbeCall(MachineFunction &MF, MachineBasicBlock &MBB,
34                                  MachineBasicBlock::iterator MBBI, DebugLoc DL);
35 
36   void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
37                                  MachineBasicBlock::iterator MBBI,
38                                  DebugLoc DL) const;
39 
40   /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
41   /// the function.
42   void emitPrologue(MachineFunction &MF) const override;
43   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
44 
45   void adjustForSegmentedStacks(MachineFunction &MF) const override;
46 
47   void adjustForHiPEPrologue(MachineFunction &MF) const override;
48 
49   void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
50                                      RegScavenger *RS = nullptr) const override;
51 
52   bool
53   assignCalleeSavedSpillSlots(MachineFunction &MF,
54                               const TargetRegisterInfo *TRI,
55                               std::vector<CalleeSavedInfo> &CSI) const override;
56 
57   bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
58                                  MachineBasicBlock::iterator MI,
59                                  const std::vector<CalleeSavedInfo> &CSI,
60                                  const TargetRegisterInfo *TRI) const override;
61 
62   bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
63                                   MachineBasicBlock::iterator MI,
64                                   const std::vector<CalleeSavedInfo> &CSI,
65                                   const TargetRegisterInfo *TRI) const override;
66 
67   bool hasFP(const MachineFunction &MF) const override;
68   bool hasReservedCallFrame(const MachineFunction &MF) const override;
69 
70   int getFrameIndexOffset(const MachineFunction &MF, int FI) const override;
71   int getFrameIndexReference(const MachineFunction &MF, int FI,
72                              unsigned &FrameReg) const override;
73 
74   int getFrameIndexOffsetFromSP(const MachineFunction &MF, int FI) const;
75   int getFrameIndexReferenceFromSP(const MachineFunction &MF, int FI,
76                                    unsigned &FrameReg) const override;
77 
78   void eliminateCallFramePseudoInstr(MachineFunction &MF,
79                                  MachineBasicBlock &MBB,
80                                  MachineBasicBlock::iterator MI) const override;
81 
82 private:
83   /// convertArgMovsToPushes - This method tries to convert a call sequence
84   /// that uses sub and mov instructions to put the argument onto the stack
85   /// into a series of pushes.
86   /// Returns true if the transformation succeeded, false if not.
87   bool convertArgMovsToPushes(MachineFunction &MF,
88                               MachineBasicBlock &MBB,
89                               MachineBasicBlock::iterator I,
90                               uint64_t Amount) const;
91 };
92 
93 } // End llvm namespace
94 
95 #endif
96